The long-term goal of this project is to develop a non-invasive, noise-based technique for enhancing somatosensation and thereby improving balance control in elderly fallers and older adults with somatosensory deficits. In previous studies, we have shown that sub-sensory mechanical noise (i.e., random vibration with a small intensity) can enhance somatosensory function in healthy individuals and older adults with somatosensory deficits. Moreover, we have shown that the postural sway of both healthy young and healthy elderly individuals during quiet standing can be significantly reduced by applying sub-sensory mechanical noise to the feet using vibrating shoe insoles. Despite these promising results, we still need to determine in which types of elderly patients this intervention is effective, whether the intervention is effective in improving dynamic balance control and clinical measures of balance in addition to quiet-standing balance control, and whether subjects adapt to the input noise that is used as part of the intervention. Thus, in this project, we plan to build upon this work and explore the effects of our noise-based technique on biomechanical and clinical measures of balance in elderly individuals with somatosensory deficits and older adults with recurrent falls. The specific aims of this project are: (1) to determine the effects of noise-enhanced somatosensation at the feet on balance performance in elderly individuals with somatosensory deficits; (2) to assess whether adaptation occurs in noise-enhanced balance control in elderly individuals with somatosensory deficits; (3) to determine the effects of noise-enhanced somatosensation at the feet on balance performance in elderly individuals with recurrent falls; and (4) to assess whether adaptation occurs in noise-enhanced balance control in elderly individuals with recurrent falls. To accomplish these aims, we will conduct quiet-standing and dynamic posture experiments and clinical balance assessments on elderly individuals with somatosensory deficits and elderly individuals with recurrent falls. These studies will utilize the RNH Epidemiology Core and the RNH Data Management and Analysis Core. This project could lead to the development of a novel bioengineering technique for improving balance control in older adults and patients with somatosensory deficits. The proposed work could thus serve to reduce the frequency, morbidity and cost of falling, and assist aged individuals in achieving maximal independence in activities of daily living and mobility.